N-[(phosphinyl)amino]thio- and N-[(phosphinothioyl)amino]thiomethylcarbamates, a process for preparation and formulations of them suitable for pesticidal use are shown in U.S. Pat. No. 4,081,536 issued Mar. 28, 1978. Phosphoroaminosulfenyl derivatives of benzofuran carbamates and preparation thereof are disclosed in U.S. Pat. No. 4,024,277 issued May 17, 1977. These phosphorus acid derivatives of aminothiomethylcarbamate pesticides are among the compounds prepared by the novel processes of the present invention and, therefore, the above patents can be referred to for relevant status of the art.
Other prior art includes a detailed report describing the synthesis of dialkylaminothio derivatives of N-methylcarbamates by C. E. Hatch in J. Org. Chem., 43, 3953 (1978) which utilizes dialkylaminothiocarbamoyl fluorides in the synthesis of carbamate derivatives. This report also describes a preparation of N-methylcarbamoyl fluoride which contrary to the present invention uses solvents and excess hydrogen fluoride in the preparation thereof. Production of another carbamic acid fluoride is found in a process of Switzerland Pat. No. 422,755 claiming a German filing date of Feb. 20, 1961 by Farbenfabriken Bayer A. G. as disclosed in Derwent Abstract No. H1400 (=11,603). This process provides for the use of hydrogen fluoride as reactant and solvent, optionally with other solvent in a reaction with a substituted phenyl isocyanate thus also not teaching the advantages of the invention described herein.
Disclosures of a preparation for N-chlorothio-N-methylcarbamoyl fluoride and a preparation for N-chlorothio-N-methyl carbamoyl chloride, subsequently denoted as Formula IV herein are found in German Offenlegungsschriften 1,931,054 and 2,023,079 (fluoride) and U.S. Pat. No. 3,699,163 (chloride).
Further background teaching phosphoramide reactants denoted as Formula V herein is found in Methoden der Organischen Chemie (Houben-Weyl) Vol. 12, part 2, pages 610, 760 (thiophosphoramides) and pages 276, 413 (phosphoramides) Georg Thieme Verlag (Pub.), Stutgart, Germany, 1963. In addition L. Anschiitz et al., Ber. 61, 1264 (1928) teaches a benzothiophosphol chloride from which the corresponding amides of this invention can be made.